检索结果-内蒙古大学图书馆

Optical, mechanical and tribological properties of Y2O3, Er2O3 and Nd2O3 doped polycrystalline silicon nitride ceramics

引用

IOP Conference Series: Materials Science and engineering 2011年第8期18卷

作者： Bhupendra Joshi Zhengyi Fu Koichi Niihara Soo W Lee Department of Metallurgy and Material Engineering Sunmoon University Korea State Key Lab of Advanced Technology for Material Synthesis and Processing Wuhan University of Technology China Nagaoka University of Technology Nagaoka Japan Department of Environment Engineering Sunmoon University Asan Korea

Y2O3, Er2O3 and Nd2O3 doped polycrystalline silicon nitride ceramics were prepared by hot press sintering method at 1850°C and 30 MPa pressure. 1 wt.% of each rare earth oxides (REO) were sintered with 3 wt.% MgO, 9 wt.% AlN and 87 wt.% α-*** optical, mechanical and tribological properties of REO doped polycrystalline silicon nitride ceramics were investigated. Optical transmittance was measured in visible and near infrared region and found to be 54% transmittance for Y2O3 doped Si3N4 ceramics. β- phase transformation was suppressed with REO addition. High hardness and high fracture toughness were achieved by addition of REO. Adding REO shows good mechanical properties as high strength and toughness. Coefficient of friction of the REO doped silicon nitride ceramics was lower than that of without REO doped silicon nitride ceramics.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Fabrication of translucent boron nitride dispersed polycrystalline silicon nitride ceramics

引用

IOP Conference Series: Materials Science and engineering 2011年第1期20卷

作者： B Joshi Z Fu K Niihara S W Lee Department of Metallurgy and Material Engineering Sunmoon University Korea State Key Lab of Advanced Technology for Material Synthesis and Processing Wuhan University of Technology China Nagaoka University of Technology Nagaoka Japan Department of Environment Engineering Sunmoon University Asan Korea

Optical transparency was achieved at infrared region and overall translucent silicon nitride was fabricated using hot press sintering (HPS). The increase in h-BN content decreased the optical transparency. Microstructral observations shows that the optical, mechanical and tribological properties of BN dispersed polycrystalline Si3N4 ceramics were affected by the density, α:β-phase ratio and content of h-BN in sintered ceramics. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO and h-BN at 1850°C. The composite contained from 0.25 to 2 mass % BN powder with sintering aids (9% AlN + 3% MgO). Maximum transmittance of 57% was achieved for 0.25 mass % BN doped Si3N4 ceramics. Fracture toughness was increased and wear volume and friction coefficient were decreased with increase in BN content.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Fabrication of (Ti, Si, O, N)/Ti composite coating on NiTi shape memory alloy using PIIID and coating evaluation

引用

2009 MRS Fall Meeting

作者： Sun, Tao Wang, Lang-Ping Wang, Min Department of Mechanical Engineering University of Hong Kong Pokfulam Road Hong Kong Hong Kong State Key Lab. of Advanced Welding Production Technology Harbin Institute of Technology Harbin China

ISBN: (纸本)9781605112121

A compact and uniform (Ti, Si, O, N)/Ti composite coating was fabricated on the surface of a NiTi shape memory alloy (SMA) (containing 50.8 at.% Ni) using plasma immersion ion implantation and deposition (PIIID) with radio-frequency (RF) magnetron sputtering. The coating and coated NiTi SMA were studied using various techniques. Analysis showed that the Ni content was drastically reduced on the surface of coated samples due to coating formation. This could greatly improve the biocompatibility of NiTi SMA. There was no TiO2 or TiN formation in the coating. The shape memory ability of NiTi SMA samples was no deteriorated by the coating process. The coating significantly improved the corrosion resistance and wear resistance of NiTi SMA and also rendered the material bioactive. © 2010 Materials Research Society.

关键词： Composite coatings

来源：评论

学校读者我要写书评

暂无评论

Residual stress relaxation of cubic boron nitride thin films deposited in Ar with other noble gases

引用

IOP Conference Series: Materials Science and engineering 2011年第1期20卷

作者： T Ohori J Shirahata T Suzuki T Nakayama H Suematsu S W Lee Z Fu K Niihara Extreme Energy-Density Research Institute Nagaoka University of Technology Niigata 940-2188 Japan Department of Environmental Engineering Sun Moon University Chungnam 336-708 Korea State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

A novel method based on radio frequency magnetron sputtering tailored to the deposition of low residual stress and adherent c-BN thin films on silicon substrates was developed. In this study, the effect of noble gas (Kr, Ar, Ne and He) added in Ar gas during sputtering on the residual stress and the c-BN content has been investigated. As a result, it was found that the residual stress of c-BN thin film decreased with increasing the helium gas flow rate within argon gas.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Particle size control of silver nanoparticles prepared by pulsed wire discharge in liquid media

引用

IOP Conference Series: Materials Science and engineering 2011年第1期20卷

作者： Y Tokoi K Josho Y M Izuari T Suzuki T Nakayama H Suematsu S W Lee Z Fu K Niihara Extreme Energy-Density Research Institute Nagaoka University of Technology Niigata 940-2188 Japan Department of Environmental Engineering Sun Moon University Chungnam 336-708 Korea State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Silver nanoparticles were prepared by pulsed wire discharge (PWD) using silver wire in deionized water at various relative energy (K) from 10 to 98, which is ratio of the charged energy of the capacitor in the electrical circuit to the vaporization energy of the wire. From energy deposition calculated by the measured voltage and current waveforms, deposited energy of the wire was increased with increasing K. From X-ray diffraction (XRD) analysis, prepared nanoparticles were phase identified as silver. From transmission electron microscopy observations, the shape of prepared silver nanoparticles were spherical and the median particle diameter (D50) and the geometric standard deviation (σg) were calculated from the particle distribution. D50 was decreased from 34 to 19 nm with increasing K. The particle size in prepared by PWD in liquid media can be controlled by K.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation of mechanical controlling parameters for Type IV cracking on the welding joints of martensitic heat-resistant steel

引用

中国高等学校学术文摘·材料科学 2010年第2期4卷 210-216页

作者： Jian-Qiang ZHANG Bing-Yin YAO Tai-Jiang LI Fu-Guang LIU Ying-Lin ZHANG State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China School of Power and Mechanical Engineering Wuhan University Wuhan 430072 China Xi'an Thermal Power Research Institute Co. Ltd Xi'an 710032 China School of Power and Mechanical Engineering Wuhan University Wuhan 430072 China

The maximum principal stress, von Mises equivalent stress and equivalent creep strain in the welding joint of martensitic heat-resistant steel (9CrlMoVNb) are simulated by finite-element method (FEM) under the condition of 600℃ and applied stress of 80MPa. The results show that the maximum principal stress and von Mises equivalent stress are high on the curved points of two sides of the groove face near the fine-grain heataffected zone (HAZ). The creep strain mainly concentrates in the fine-grain HAZ; the maximum creep strain locates in the bottom of fine-grain HAZ of specimen. The stress triaxiality in the fine-grain HAZ is maximum, and creep cracking occurs because of the intensive constrain of base metal and weld. The simulation result is good in agreement with those of crack initiation site and propagation path by using the stress triaxiality as the mechanical controlling parameter of weld joint of martensite heat-resistant steel. Therefore, it is reasonable that the stress triaxiality is used for analysis initiation and propagation of Type IV cracking in the fine-grain HAZ.

关键词： martensitic heat-resistant steel Type Ⅳ cracking von Mises equivalent stress equivalent creep strain numerical simulation

来源：评论

学校读者我要写书评

暂无评论

Fabrication of (Ti-O-N-Si)/Ti Composite Coating on NiTi Shape Memory Alloy Using PIIID and Coating Evaluation

引用

MRS Online Proceedings Library 2010年第1期1239卷 1-6页

作者： Tao Sun Lang-Ping Wang Min Wang Department of Mechanical Engineering The University of Hong Kong Hong Kong State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin China

关键词： biomaterial coating physical vapor deposition (PVD)

来源：评论

学校读者我要写书评

暂无评论

Preparation, properties, and thermal control applications of silica aerogel infiltrated with solid-liquid phase change materials

Preparation, properties, and thermal control applications of...

引用

作者： Xiangfa, Zhou Harming, Xiao Jian, Feng Changrui, Zhang Yonggang, Jiang Department of Materials Science and Engineering Hunan University Changsha 410082 China State Key Lab. of Advanced Ceramic Fibers and Composites College of Aerospace and Materials Engineering National Univ.of Defense Technology Changsha 410073 China

ISBN: (纸本)9781439834015

In the present work, silica aerogel saturated with erythritol as phase change materials (PCMs) was prepared by melt infiltration. In the novel composite, erythritol with high latent heat of fusion was used as PCM for thermal control, whereas nanoporous silica aerogel was prepared as the phase change matrix to provide structural strength and prevent leakage of melted erythritol. Nitrogen gas adsorption curves and SEM analysis indicate that the pore structure of silica aerogel was porous and connected with each other. FTIR analysis showed that the composite formation of silica aerogel and erythritol were physical, whereas DSC analysis showed that the melting point and heat storage capacity of the composite were 123.8°C and 289.92 kJ/kg, respectively. The thermal protection properties of phase change composites were designed under laboratory conditions using a thermal measurement setup of a simulated thermal environment of an aircraft. Compared with the paraffin-silica aerogel composite, the erythritol-silica aerogel composite could rapidly control the rising temperature by absorbing heat under high thermal environments.

关键词： Sol-gel process

来源：评论

学校读者我要写书评

暂无评论

Influence of oxygen content on hardness of Cr(N,O) thin films deposited by an RF sputtering method

引用

IOP Conference Series: Materials Science and engineering 2011年第1期20卷

作者： J Shirahata T Ohori H Asami T Suzuki T Nakayama H Suematsu S W Lee Z Fu K Niihara Extreme Energy-Density Research Institute Nagaoka University of Technology 1603-1 Kamitomioka Nagaoka 940-2188 Japan Department of Mechanical Engineering Tomakomai national college of Technology 433 Nishikioka Tomakomai 059-1275 Japan Department of Environmental Engineering Sun Moon University Chungnam 336-708 Korea State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Cr(N,O) thin films were deposited by radio frequency reactive unbalanced magnetron sputtering on Si(100) or glassy carbon substrates. In this paper, the influence of oxygen content on hardness of Cr(N,O) thin films was investigated. The compositional analysis was carried out by Rutherford backscattering spectroscopy. It was found that these thin films contained up to 44at.% of oxygen. Phases in the samples were determined by X-ray diffraction. Cr(N,O) thin films show only peaks based on CrN. The microstructure was observed by utilizing a transmission electron microscope. At <1at.% of oxygen, crystallite size was approximately 100nm. Then, in accordance with increasing of oxygen content, crystallite size was decreased. The hardness of thin films was measured by using a nanoindenter. The micro hardness was changed with varying the oxygen content and the microstructure such as crystallite size. Thus, it was thought that the hardening on Cr(N,O) thin films was caused by solution hardening and/or Hall-Petch relationship.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A novel Nth-order microstrip dual-mode bandpass filter with N+2 transmission zeros

A novel Nth-order microstrip dual-mode bandpass filter with ...

引用

2010 International Conference on Microwave and Millimeter Wave technology, ICMMT 2010

作者： Shen, Wei Yin, Wen-Yan Sun, Xiao-Wei Wu, Lin-Sheng Center for Microwave and RF Technologies School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 China Center for Optical and Electromagnetic Research State Key Lab. of MOI Zhejiang University 310058 China Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

ISBN: (纸本)9781424457052

A novel Nth-order microstrip filter with N+2 transmission zeros using two dual-mode resonators is presented in this paper. Two different coupling schemes are obtained by changing couplings between dual-mode resonators and ports. Then, two fourth- and second-order filter characteristics with three and four transmission zeros are obtained correspondingly. The generation mechanism of transmission zeros is interpreted in detail by coupling matrix theory. A microstrip dual-mode filter is designed and fabricated, with good agreement achieved between the measured and the simulated S-parameters. © 2010 IEEE.

关键词： Bandpass filters

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：